PAMILY CARES — BUILDING THE HOME. 149 



by brooding over them. Soon the latter fashion 

 would prevail entirely. Then, it may have been 

 that those which had to lay their eggs in damp 

 places would discover the advantages of saving 

 their treasures from actual contact with the 

 ground by first making a sort of bed of dry 

 grass or sticks. Just as the common swan, for 

 instance, will add material to its nest to raise the 

 eggs, immediately before a flood, the coming of 

 which it seems to anticipate instinctively. Later, 

 from various causes, and in ditierent times and 

 places, such birds would be driven to seek refuge 

 in trees and bushes for the greater security of 

 themselves or their eggs; and would then con- 

 struct, as best they could, a receptacle among 

 the branches precisely similar to that which 

 they had previously built on the ground. This 

 receptacle we call a "nest."' Indeed migration 

 so to speak from the ground to the tree.^, or 

 rice versa, happens commonly to-day. Birds 

 like the herons for instance that usually build 

 in lofty trees will, in the absence of these, 

 make their nest upon the ground ; whilst gulls, 

 ducks, and other ground-building birds, will 

 often nest in trees. 



At first rude, and more or less untidy structures, 

 it would seem that as the bird's aesthetic sense 

 and love of the beautiful developed, more pains 

 and care were taken in the construction of the 

 nest. Another contributing cause may have 

 been the need of disguise for the purposes of 

 protection. The addition cf moss, lichen and 

 pieces of bark on to the outside of the nest 

 caused it to blend so perfectly with the trunk 



